[PATCH 49/63] Restore "drm/i915: drop engine_pin/unpin_breadcrumbs_irq"

[Chris Wilson]

This was removed in commit 478ffad6d690 ("drm/i915: drop
engine_pin/unpin_breadcrumbs_irq") as the last user had been removed,
but now there is a promise of a new user in the next patch.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Reviewed-by: Mika Kuoppala <mika.kuoppala at linux.intel.com>
---
 drivers/gpu/drm/i915/gt/intel_breadcrumbs.c | 24 +++++++++++++++++++++
 drivers/gpu/drm/i915/gt/intel_breadcrumbs.h |  3 +++
 2 files changed, 27 insertions(+)

diff --git a/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c b/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c
index 38cc42783dfb..9e67810c7767 100644
--- a/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c
+++ b/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c
@@ -310,6 +310,30 @@ void intel_breadcrumbs_reset(struct intel_breadcrumbs *b)
 	spin_unlock_irqrestore(&b->irq_lock, flags);
 }
 
+void intel_breadcrumbs_pin_irq(struct intel_breadcrumbs *b)
+{
+	if (GEM_DEBUG_WARN_ON(!b->irq_engine))
+		return;
+
+	spin_lock_irq(&b->irq_lock);
+	if (!b->irq_enabled++)
+		irq_enable(b->irq_engine);
+	GEM_BUG_ON(!b->irq_enabled); /* no overflow! */
+	spin_unlock_irq(&b->irq_lock);
+}
+
+void intel_breadcrumbs_unpin_irq(struct intel_breadcrumbs *b)
+{
+	if (GEM_DEBUG_WARN_ON(!b->irq_engine))
+		return;
+
+	spin_lock_irq(&b->irq_lock);
+	GEM_BUG_ON(!b->irq_enabled); /* no underflow! */
+	if (!--b->irq_enabled)
+		irq_disable(b->irq_engine);
+	spin_unlock_irq(&b->irq_lock);
+}
+
 void __intel_breadcrumbs_park(struct intel_breadcrumbs *b)
 {
 	if (!READ_ONCE(b->irq_armed))
diff --git a/drivers/gpu/drm/i915/gt/intel_breadcrumbs.h b/drivers/gpu/drm/i915/gt/intel_breadcrumbs.h
index 3ce5ce270b04..c2bb3a79ca9f 100644
--- a/drivers/gpu/drm/i915/gt/intel_breadcrumbs.h
+++ b/drivers/gpu/drm/i915/gt/intel_breadcrumbs.h
@@ -19,6 +19,9 @@ struct intel_breadcrumbs *
 intel_breadcrumbs_create(struct intel_engine_cs *irq_engine);
 void intel_breadcrumbs_free(struct intel_breadcrumbs *b);
 
+void intel_breadcrumbs_pin_irq(struct intel_breadcrumbs *b);
+void intel_breadcrumbs_unpin_irq(struct intel_breadcrumbs *b);
+
 void intel_breadcrumbs_reset(struct intel_breadcrumbs *b);
 void __intel_breadcrumbs_park(struct intel_breadcrumbs *b);
 
-- 
2.20.1